On Oct10, 2011, at 19:41 , Jeff Davis wrote:
> On Mon, 2011-10-10 at 19:22 +0200, Florian Pflug wrote:
>> I still think we should strive for consistency here, so let's also make
>> '[]' the default flags for the range constructors.
>
> For continuous ranges I don't think that's a good idea. Closed-open is a
> very widely-accepted convention and there are good reasons for it -- for
> instance, it's good for specifying contiguous-but-non-overlapping
> ranges.
It really depends on what you're using ranges for. Yeah, if you're "convering"
something with ranges (like mapping things to a certain period of time, or
an area of space), then half-open ranges are probably very common.
If, OTOH, you're storing measurement with error margins, then open ranges,
i.e. '()', are probably what you want.
I still firmly believe that consistency trumps convenience here. Specifying
the range boundaries' exclusivity/inclusivity explicitly is quite cheap...
> So, I think we either need to standardize on '[)' or allow different
> default_flags for different types. Or, always specify the inclusivity in
> the constructor (hopefully in a convenient way).
In the light of Tom's argument, my pick would be '[]'. It's seem strange
to normalize ranges over discrete types to closed ranges, yet make the
construction function expect open boundaries by default.
best regards,
Florian Pflug